Heat-treatment of 2014 aluminium alloy forgings with intense strain

The triangular 2014 aluminium alloy forgings with intense strain were made by a variety of heat-treatment processes, and their mechanical properties were measured. The results showed that different solution and aging processes have very strong influence on the mechanical properties of the forgings. The forgings with intense strain from multidirectional deformation (deformation coefficient lambda = 12), which were solutioned at 500 degreesC for 400 min and aged at 165 degreesC for 10 h, show advanced mechanical properties, and almost no anisotropies. The mechanical properties are sigma (b) = 466 MPa, sigma (0.2) = 454 MPa, delta = 10.5% along LD; sigma (b) = 457 MPa, sigma (0.2) = 444 MPa, delta = 6.3% along TD; sigma (b) = 449 MPa, sigma (0.2) = 433 MPa, delta = 4.2% along HD. The yield strength of the forgings made by a new process was improved by 30% to 50%, the ultimate tensile strength by 15% to 30% and elongation by 100% to 200%, compared with the mechanical properties of the forgings made by the traditional process. The investigation indicated that the very fine grains (3 similar to6 mum) and the sub-microphases(0.05 similar to 0.15 mum), and their homogeneous distribution have made the forgings have the high mechanical properties.